Centrifugal compressor.



0I BANNER.

TRIFUGAL COMPRESSOR. lIPPLILATION FILED IIAR. 21, 191m Patented Jan. I4,1913.

L-lge.

w/msssfs iTan sTaTTs raTieNT @FFME OTTO BANNER, OF EASTON, PENNSYLVANIA,ASSIGNOR TO INGERSOLL-RAND GOM- PNY, OF NEW YORK, N. Y., A CORPORATION0F NEW JERSEY.

CENTRIEUGAL COMPRESSOR.

Lasarte.

Specification of Letters Patent.

Patented Jan. 1.4L, 1913.

Application led March 21, 1912. Serial No. $85,226.l

To all whom t may concern.'

Be it known that l, Orro BANNER, subject of the German Emperor, residingat Easton, in the State of Pennsylvania, have invented certain new anduseful Improyements in Centrifugal Compressors, of which the followingis a specification. p

This invention relates to multi-stage centriifugal turbo compressors forair and similar fluids, and more particularly to the design of theblades, and the radial distance ot the inner ends of the blades in theimpellers of such machines.

The machines at present used are made up of a series of impellers, theblades of which are all set at approximately the same angle on theimpeller disks. A. constant ratio between the radial distance of theinner ends of the blades ot the mpellers and their radii is likewisegenerally. maintained. ln the construction of these machines greatdidiculty is experienced in the impellers in the high pressure stages,particularly in machines of small capacity. In order to provide for thedecrease involume of the air from impeller to impeller or from stage tostage, it is necessary to decrease the blade width and hence the area ofthe peripheral orifice of the impeller. Another Way of decreasing thisarea, and at the same time the force impelling the air outward, is todecrease the diameter of the impellers. In practice both of thesemethods are resorted to, but in the higher stages of a compressor of lowcapacity it becomes almost impossible to construct the impellers with asmall enough peripheral orifice to get the proper decrease in the volumeof the air and hence the eiciency. s

The object of my invention is to so design the blades of the impellersthat it is possible to maintain the impeller orifice of a Width whichcan be constructed without diculty and yet at the same t-ime to attain ahigh degree of eciency in the impeller.

With this object in view, l increase the angle or" the impeller bladesand at the same time decrease the ratio of the radial distance of theinner ends of the blades to the radius of the impeller, from stage tostage or inthe last stage or stages. The advantage obtained thereby isan increase in the ease and consequently a decrease in the cost ofFigure-.l is a side elevation partly in section of the completecompressor. Fig. 2 is a diagrammatic showing of the position of l theblades in the impeller in the first stage. Fig. 3 is a section on largerscale through the iinpeller shown in Fig. 2. Fig. lis a diagrammaticshowing of the position of the blades .in the impeller in the laststage, and Fig. 5 is a section on a larger scale through the impellershown in Fig. 4.

"The compressor comprises a horizontally divided casing made up of alower casing or base 1, and anupper casing 2. In bearings 3, 4, on thebase is journaled the shaft 5, on which are mounted a plurality ofinipellers of the same diameter which consist of disks G, 7, 8. 9,blades 10, 11, 12, 13, and covers 14, 15, 16, 17. The impellers ...recon nected by air passages 18, 19, 20, which are provided with the usualguide varies, and the air enters the compressor by the inlet chamber 21,which is supplied by any convenient opening, in this case through thebase 1, and is taken out through exhaust chamber 22 and exhaust pipe 23.

The usual water jacket 2-1 is provided.

ln the first impeller the blades 10 have a comparatively small angle ofinclination, and the air leaves the impeller with comparative ease. Inthe last stage, the blades 13 have a large exit angle and approach muchmore nearly to a tangential position at their outer ends, thus retardinthe air to a considerable extent and causin it to pass `through theimpeller with considerable less velocity than in the first wheel. Theangles of the blades of the intermediate impellers in the presentcompressor may be either graduations between the `first and last, or inone or more impellers may be the same as the nearer end impeller.

Another feature of the present device is that in the impellers the innerends of blades 11 are nearer the shaft center than the inner ends ofblades 10 and likewise the inner ends of blades 12 and 13 aresuccessively nearer the shaft center. This feature contributes to theeciency of the machine Y:lor the impellers in a multi-stage turbocompressor to he built with a higher degree olf" eti'ioiency and withgreater ease of construction than has heretofore been known.

lt is to be understood that the present showing only discloses oneembodiment oit my intention.

lily invention contemplates using the principles herein disclosed andclaimed, in compressors ot a less or greater number ot impellers Whetherin groups olf the same design and dimensions and changing from group togroup, or changing -irons. impeller to impeller, orl changing :tromgroup to single impeller, or in any Way consonant with the principlesherein set torth. F urthermore, although my invention is particularlyadapted to compressors ci small capacity and high pressure, yet it isequally applicable in any compressor where it is desirable to lieep theimpellers ci substantially the saine dimensions Without loss or eciency.

lt is to be understood that a slight variation in the angle ot theblades Twill have no appreciable eitect and that therermnst be amaterial diderence in the eirit angle in the last impeller or impellersto accomplish the desired resnlta u mWhat l claim is: l

l, compressor, a plurality oit inipellers, the tlnirl to compressed iimpellers ries ein che last, and :lor said neonazis pellers, the bladesin the tiret inipeller hayn ing smaller enit angles than the blades olthe last impeller..

'2. in a compressor, a plurality olf inipellers, the tluid to becompressed passing through said impellers in series from the lirst tothe last, and blades t'or said impellers, the blades in one ot saidimpellers having smaller enit angles than the blades ot the impellersucceeding it,

3. ln a compressor, a plurality ol irnpellers, the fluid to loecompressed passing through said impellers in series trom the lirst tothe last, and blades lior said im pellers, the blades in successiveiinpellers harincfsuocessively greater enit angles.

el. ln a compressor, a plurality ot' impellers ot' substantially thesame diameter, the fluid to be compressed passins through said impcllersin series from the rst to the last, and blades for said impellers, theblades ot the tiret impeller having smaller enit angles than the bladesof the last impeller.

5. ln a compressor, a plurality oit iinpellers, the tluid to becompressed passing through said impellers in series iti-om the lirst tothe last, and blades tor said impellers, the blades ot the rst impellerhaying smaller crit angles than the blades ci the last im. ellers andthe ratio ot the radial distance o" the inner ends of the blades oi theiirst impeller to the radius et said impeller being greater than thecorresponding ratio in the last impeller.

8., ln a compressor, a plurality oit inipellers, the fluid to becompressed passing in series therethrough, and blades tor saidimpellers, the ratio oi the radial distance ot the inner ends ot theblades irom the shalt center, to the radius o'll the impellei 'beingless in the drst impeller than in the 'Witnesses z Lewis @l @nonLannesrnoit.

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